A keyless entry system which achieves a door lock mechanism of a car for unlocking and locking by using wireless communication has heretofore come into wide use (for example, see Non-Patent Literature 1).
A system which charges a battery of a portable communication device through communication between the portable communication device and an on-vehicle communication device has been known as the background-art keyless entry system (for example, see Patent Literature 1).
In addition, there has been heretofore known a vehicle charging system provided with a vehicle-side charging control device which has a coil for non-contact charging an on-vehicle battery loaded into the vehicle from a loop coil of an external device outside the vehicle and which transmits a charging start request signal and a charging stop request signal to the external device outside the vehicle when a predetermined condition is established, in order to prevent a bad influence on wireless communication used in the vehicle (for example, see Patent Literature 2).
A portable device such as a cell phone loaded with a rechargeable secondary battery has recently come into wide use, and development of non-contact charge has been advanced to attain further improvement in user-friendliness.